Signal transduction mechanisms of Ia induction in B cells by interleukin 4 and immunoglobulin receptors.
Molecular mechanisms of signal transduction through receptors for interleukin 4 (IL-4) are still largely unknown. To elucidate the second messenger(s) of IL-4 action in mature B cells, we performed blocking experiments with inhibitors of various aspects of cellular responses, using Ia-inducing activity of IL-4 as a readout system. In the event, only agents that are shown to inhibit calcium ion (Ca2+) release from intracellular stores, such as 3,4,5-trimethoxybenzoic acid 8-(diethylamino)octyl ester (TMB-8) and ryanodine, could block the IL-4 action in a dose-dependent fashion. These results suggest that the process leading to the final expression of IL-4 action may be mediated, at some point, by the release of Ca2+ from intracellular stores. In the parallel experiments with antiimmunoglobulin (Ig) antibody, we found that amiloride, an inhibitor of Na+/H+ pump, blocks the Ia induction by anti-IgM antibody. Thus the Na+/H+ exchange system activated by anti-Ig antibody may be present in mature B cells.
Ashida
T
T
Department of Pathology, Asahikawa Medical College, Japan.
Kubo
K
K
Kawabata
I
I
Katagiri
M
M
Ogimoto
M
M
Yakura
H
H
D000818:Animals; D000888:Antibodies, Anti-Idiotypic / Q000276:immunology*; D001402:B-Lymphocytes / Q000276:immunology*; D002118:Calcium / Q000378:metabolism; D005707:Gallic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D000949:Histocompatibility Antigens Class II / Q000096:biosynthesis*; D007075:Immunoglobulin M / Q000276:immunology; D015847:Interleukin-4 / Q000494:pharmacology*; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D015398:Signal Transduction; D012964:Sodium / Q000378:metabolism
D000888:Antibodies, Anti-Idiotypic; D000949:Histocompatibility Antigens Class II; D007075:Immunoglobulin M; D015847:Interleukin-4; C006014:8-(N,N-diethylamino)octyl-3,4,5-trimethoxybenzoate; D005707:Gallic Acid; D012964:Sodium; D002118:Calcium